garrard



April 16, 1929.

C. G. GARRARD VARIABLE SP1-:E15 GEARING Filed Sept. 23, 1927 38 Cl'arles Geur April 16, 1929. c. G. GARRARD 1,709,345

VARIABLE SPEED GEARING A Filed sept. 23. 19'2'7 2 sheets-sneer 2 Cyrle s George Galfal w 212mm .Unirse STATES PATENT OFFICE.

CHARLES GEORGE GARRERD, OF LONDON, ENGLAND, ASSIGNOR IO GARRARD GEARS LIVIITED, OF LONDON, ENGLAND, A LIMITED LIABILITY COMPANY.

VARIABLE-SPEED GEARING.

Application filed September 23. 192?, Serial No. 221,430, and. in Great Britain July 15, 1927.

`This invention relates Ato variable speed gearing and has ior its objects Vto provide such gearing byineans of which any desired speed changes may be ell'ected both in` a forward and reverse direction to give any ratio in either direction of rotation.

In general, variable speed gearing constructed according to the invention comprises at least one epicyclic train, toothed, friction, or otherwise, having the usual sun, cage or the like with satellites, and annulus elements, any two o tivliich elements are connected together through any desired torni 'of variable gear, so that the third element is left free to be connected to the shaft orv the like to be driven, which shaft in some cases may be the driving shaft.

The method of `conneeting the variable gear to `the epieyclic train may vary and in soi'necases the driving sl'ia't for the variable gear may drive directly one et the elements of the `said epicyclic train, a variably driven shaft orthe like ot' the variable gear being connected to either ot the other elements, for example to one ot the satellites carried by the cage or the like, which cage or the like may be reprifsented by a fixed casing.

The prelerrei'l Ytorni of variable gear to be connected to any two ot' the elements of the epicyclic train comprises two oppositely directed conical members o'j similar conicity with their axes parallel and a desired distance apart to leave a gap et constant dimen.- sions between the portions ol their surfaces coming adjacent, in which gap a transmitting member or members are mounted to frictionally transmit the movements ol one cone to the other, means being provided to maintain the parts in tight iti'ictional gripping and driving contact and for adjusting the position olthe transmitting member with respect to the cones. In this manner the linear speed of the conical member which is driven, in the position where Contact is made by the intermediate member, is transmitted to the cone te be driven and as a consequence the ratio of speed between the two conical members depends upon 'the position ot the transmitting member. `The parts may .be maintained in tight driving contact by imparting end thrust to one oi the cones and the means for transmitting end thrust to one of the cones which may be the driving or driven cone, preferably the latter, may be of a resilient nature such as a. spring acting to move the conical member axially or may becam means also adapted to cause axial movement. To act as a balancing means for journal thrust and orgenerally equalizing the drive of the variable gear, ytwo or more similar conical members may be arranged at desired and preferably equisangular distances apart around a central and oppositely directed conical member and the radially arranged conical members may be carried by bearings, for example a cage held in position by Heating rings, the radial thrust outwards holding the parts in position.

The intermediate transmitting member between the central cone andthe other cone or cones may be constituted by two or more suitably mounted balls, rollers or the like, but

in preferred forms between the central member and eaclicone a reely rotating ring 1s provided. Each ring is of desired diameter and the section of the material ofthe ring is` preferably such that its greatest dimension equals the dimension between the surfaces of the cones, the inner and outer surfaces of the ring being curved with a similar curvature. Means are provided for varying the position of the intermediate transmitting member in a longitudinal direction and where more than i reference to Vthe accompanying drawings in which Figs. l, 2 and 3 `show sectional plans of a number of gears constructed according to the invention.

Fig. 1l shows a diagram 4of another variation.

Figs. 5, 6 and 7 show fragmentary cross section views of the gears, `illustrating the method ot' operating the variable gear portion of the device. Y

Many forms of gears can be devised-wherein the invention may be employed, for eX- ample the variable portion of the gear can be so connected to the epicyclic train that a constant drive is given to the central shaft or sun,pinion and a variable drive to the cage, which results in the ring being the 4driven member. Similarly, a constant drive can be given to the cage, and a variable drive to the sun member or central shaft which also results in the ring being the driven member. lith other forms a constant drive can be given to the central shaft or sim member, a variable drive to-theiring orannulus, the result being that the cageis the driven member. llith other arrangements the cage can have the constant drive Whilst the ring has the variable drive. the sun member being driven.

With still further arrangements the ring may have the constant drive Whilst either the sun orl the cage has lthe variable drive, the remaining element being the driven member. 'Annmberwof these arrangements is shown ony'the accompanying drawings.

`For theipurpose of carrying the invention into practical etl'ect anepicyclic li. ving ithree moving members is provided; one of the members is connected to the driving shaft, the secondi to the-shaft to be driven, Whilst tliethirdmember isconnected to or has ranged alongside and integral therewith or rgeared=thereto,.a conical drum of hardened and polished steel or other suitable material.

A. variety of sucharrangcments is shown on'the drawings and in litig.` `l, 3 is driving` pulley which is connected by suitable studs fanddistance pieces to the cage 9 of an epilcyclic gear, the 1eagevhaving a shaft O ivhi is supported `in suitable `bearings not shown inthe drawings. 'lhe studs and distance pieces'of the cagehave rotating thereon satel- Tlite or planet pinions 11 which mesh with a sun pinion 12and-Yivitn a toothed ring or annui-usV213;` rlhe sun pinion 12 is mounted on the'end of a shaft 14 which has .formed i with ormounted"thereon a conical drum 15 of hardened and polished steel or other suitable material. The shaft 14 is supported in a rol-ler bearing 16 in theiinte'rior of a sleeve 17 keyed toa sleeve-like extension of the boss Yof the driving pulley 8. vThis sleeve 1'? has formed wither attached to one end thereof a toothed Wheel 18 which meshes i Wit n. a toothed pinion 19 on a shaft 20 supported in suitable bearings in acasing 21. .The shaft 2() has keyed thereto a secondary conical `drum 22 `and this drum 22 isV driven by the pin-ion 19- inthe following manner. The

boss of the pinion 19 is formed at 23 with a cam surfaceof a somewhat Wedge-like nature which rio-operates with a corresponding wedged' boss 24 onlthe drum 22, the arrangement being such that When power is applied for transmission and the pinion 19 is driving the roller 22, the roller is forcedby the cam surface ofthe pinion in `thedirection of the `arrow'25, andthe conical members are maintained in tight `.driving contacts with the transmittingmember. Y

As Will be seen, the secondary drum 22`is arrangedfparallel tothe first mentioned conical drum Abuttapering in the opposite direc mettais nism comprising fork-like jaws 27 (Figs. 1

and 5) coming oneither side of the ring ,Y

mounted upon a sliding rod 28 in connection with any suitable operating mechanism (not shown). The internal andexternal surfaces of the ring 25 Which come in contact with the conical drums 15 and 22 are curved as sliovvn by the section of the ring. The axial thrust diie to 't ie co-acting cam surfaces 23 and 24 of the conical roller 22 serves to keep the cones 15 and 22 and the ring 26 i tight frictional driving Contact. fis will be understood, the driving pulley 3 causes the toothed wheel 18 to drive'the pinion 19 which in turn causes the drive of the conical roller 22 and this transmits the drive to the conical roller 15, and to the sun pinion 12. The conical roller 15 is variably driven from the conical roller according to the position into which the ring 26 is moved by the striking gear 27 and 28.

lt Will'be seen from the above that a consii-ant drive is imparted to the cage 9, and a variable drive to the sun pinion 12,and as a consequence the annulus or ring 13 is driven variably and transmits its drive to the pulley ln some casesmore'than one secondary conical drum 22 may be provided arranged parallei to the primary conical drum and tapering in the opposite direction. i

ln the form of the device shown in Fig; 2 i the epicyclic train is of the frictional type Y with somewhat `spherical surfaces on the satellites `engaging With concavities on the sun and annulus members by friction, means i'referably boing provided setting up axial thrust to give the required frictional adhesion. ln this `ligure, 30 is an engine shaft having a Ey Wheel 31 bolted thereto. lThis engine shaft has keyed thereto a shaft 32 n'iountedin ball bearings in a fixed casing 33, the said shaft 32 being provided with a primary conical member An extension of the boss of this conical member 34 is formed with radial projections 35 co-acting v-:ith cam surfaces 36 on the boss of the frictional sun pinion 37. It Will thus be seen that the sun pinion 37receives a constant drive from the shaft 30 and an axial thrust by the coacting parts 35 and 36.

38 are the frictional satellites carried by a cage 39 having an extended boss 40to which is bolted a frictional central member 41 .engaging with vfrictional planet members 42 towards the ends of the spindles of three secondary conical members 43. rllie actual ends of the conical. members 43 are mounted in bearings 44 supported by the casing 33. 45 is a floating annulus co-acting With ithe satellite members 42 and at the other ends of the secondary members 43 other satellite frictional members46 are provided with Which the float-ing frictional annulus 47 engages.

A number' of displaceable floating rings 26 are provided which come between the `primary and secondary arms 34 and 43 in a manner similar to that described with regard to the ring 26 and conical members l5 and 22 in Fig. l.. In this case three rings 26 are provided all operated by a striking gear 48 in connectionwith a sliding rod 49. Fig. 7 shows the arrangement of the rings 26 and rollers 34 and 43. By sliding the rod 49 the rings `26 can be brought into any desired position between the rollers 34 and 43. By this means the cagel 39 is given a variable `drive from the sun pinion 37 and as a consequence the annulus 50, that is to say the third member of the epicyclic train, is given a varied drive, which is impart-ed to the shaft l, which is the shaft to be driven.

Referring to the form shown in Fig, 3, in this case the arrangement is such that a constant drive is applied to the cage 52 from an engine shaft 53 having a fly wheel 54 thereon, the cage being connected to a frictional sun pinion 55 driving a number of secondary rollers 56 in a manner as set forth in the form shown in Fig. 2 which in turn rives a primary conical member 57 through the floating rings 58, the structure of these parts being also similar' to that shown with reference to F 2 and 7. conical member 57 through projecting and cam members 35 and 36 similar to those described with regard to Fig. 2 drives the sun pinion 59 in a variable manner. As a con sequence the ring or annulus 60 is driven by the` planet or satellite members 52 and imparts its motion to a shaft 6l passing loosely through the hollow shaft of the sun pinion 59 and the hollow shaft of the primary conical member 57 as shown. The shaft 6l is mount ed in suitable bearings 62. g

rI'he arrangement illustrated diagrammatically in Fig. 4 shows a case where a fric- Vtional sun pinion 63 is driven from a driving shaft 64 which has a primary cone 65 thereon. This primary cone variably drivesa secondary cone through the floating and dis placeable ring26, a frictional satellite 67 driving a ring 68 coupled to another ring 69 driving a frictional satellite 70 carried by a cage 7l attached to a shaft 72 to be driven. The drawing is only diagrammatic and it will be understood that to obtain a balanced action a number of secondary conical members 66 with associated satellites 67 would be employed as well as a number' of satellites 7 O and a cage 71 co-operating with the sun pinion 63..

Fig. 6 shows a view somewhat similar to Figs. 5 and 7 but in this case only two oating rings 26 are employed co-operating with the primary and secondary conical rollers, with `one floating ring co-ordinating the movements of the two secondary conical members.

The primary Thespeed ratio of the conical drums and the epicyclic gearing 1n all cases is preferably arranged in such a manner that when any reduction of speed is taking lace between the driving anddriven mem ers, the surface speed of the conical drum is hierher than when the driving or driven mem ers are running at the same speed, thus obtaining the required increased torque without 'abnormally increasing Athe pressure required p for adhesion of the rolling surfaces.

the driven member is held stationary, and

the drivin-g member rotated, the centre pinion will rotate four times the speed of the driving member and therefore when the speed of the centre pinion is altered to less than four times of speed of the driving mem ber, the driven member or outer ring of gear will be caused to rotate in the same direction.

As the speed of the centre member or pinion is further reduced until it is rotating at the same speed as the driving member, the driven member will be caused to also rotate at the same speed as the driving member giving a straight through drive with no reduction of speed. Similarly if the speed of the centre pinion is caused to be greater than four times the driving member, the driven member will be rotated in the opposite direction giving a reversal of motion which can be increased to any desired ratio to the driving member, but in the opposite direction.

To control and rotate the centre pinion is the function of the before mentioned conical drums; the secondary conical drum or drums are geared to the driving member so as to have any desired ratio of speed which for the sake of illustration may be the same as the epicy clic train before mentioned, and the ratio of diameter of the conical drums to each other may be varied as desired to suit requirements. For example in somecasos the ratio may be from four to one up to one to two. The secondary conical drum or drums which are geared to the driving member will therefore rotate at a fixed relative speed to the said driving member while the primary conical drinn which is connected to the centre pinion will be rotated by the adhesion of the transmission members placed between the conical drums. As the transmission members are moved laterally they will be in contactY with ofthe driven member in either direction of rotation according to their lateral position along` the conical drum or drums.

To'obtain the necessary binding pressure for adhesion upon the Heating transmission members one or moreel` the conical drums as before described have axialor lateral pressure applied by cams or springs, or any other suitablemeans maybe used for the purpose. rllhe i reaction to the binding pressure may be taken upon'the journal bearing of theiconical drums in gears ior small power, but in large power gearsvtwo or more secondary conical drums are arranged as bei'ore described in epicyclic formation Aaround the. primary conical drum and at each end of the secondary drums,

` secondary drums and one primary drum are arranged on a common centre, is by allowing the encircling rings coasting-with the parallel portions to Vfloat as before described.

For moving laterally the transmission members subjected to bindingv pressure, l arrange that the operating slide causes the rings',` rollers or the like to tilt and thus give spiralling s action between the two conical drums..V To give the necessary tilt as desir-ed in either direction when rollers are employed the housing ofthe rollers is suspended upon a hinge at right angles to their running anis with a'limited and adjustable motion whereby any movement of the controlling slide will tilt y or skew the rollers causing them to more laterally until they overtake the controlling slide when thc'tilting Will automatically correct itself.

When balls instead of rollers are used between the conical drums, the housing is arranged so that the balls are free to rotate in any direction enabling movement to take place laterally whilesubject to binding pressure-andA rotating` in their normal direction, by any suitable sliding mechanism.

Alternatively and preiierably,as before eX- plained, instead' oi using rollers or balls to transmit power from vthe one conical drum to the other a surrounding ring is used or both a ring and rollers or balls which ring passes modelle between and `is gripped between the conical members.

Any type of gearing may be used for driv-` ingthe conical drums; also the conical drums may be placed at any convenient angle to the driving members by interposing shew or bevel gearing. c

The control oi speed Variation may be arranged automatically by a governor controlling the tilting of rin rollers orv tlie like between the conical drums, or alternatively the tilting may be vcontrolled by the reactional torque acting upon an adjustable spring.

F or disconnecting the powery transmission any suitable form oi clutch may be used with, or as part oi the gearing described.

The invention is not limited to the precise forms or details oli construction described as these may be varied to suit particular cases.

What l clain'i and desire to secure by Letters Patent of the United States of America l. ln a variable speed gearing oil the type.

memberengagingsuitably 'formed portions oi'` tho secondary conical members.

2. ln variable speed gearing of the type descri sed, a primary conicalmember, condary conical members arranged around the primary conical member, coacting movable transmission members between the primary conical men'ib-er and the secondary conical members, a. trictional annnlus member engaging suitably stormed portions oi the secondary conical members, and a power transmission connection with the secondary conical members.

3. ln a variable speed gearing oi the type described, a primary conical member, secondary conical members arranged around the primary conical member, coacting;r movable transmission members between the primary conical member and the secondary conical members, and a pair oij friction-al annulus members 'engaging the secondary conical members and betnf'een which the coned portions are located.

ln witness whereof aiiclr; my signature.

' CHARLES GEORGIE GllllilnRD. 

